Todd Rice, a lifeguard at San Diego's Mission Beach, said he was on a paddle board shortly after noon Aug. 25 when he saw an 18-inch fin stick out of the water. He said it was a great white.

"Yeah, I was scared obviously," he told KGTV. "It's a pretty big fish."

And it's not just San Diego. In Florida this summer, two surfers were riding a wave when a shark burst out of the water. And off the coast of Rhode Island, tourist Bruce Lechleiter of Dayton, Ohio, snapped a picture of a fin near swimmers.

Where There Are Seals, There Will Be Sharks

Experts say sharks are showing up in unusual places because populations of seals -- sharks' favorite meal -- are exploding off both U.S. coasts.

And near Cape Cod, Mass., there have been 35 great white sightings this year.

"You always have to be a bit nervous because a seal might pop up," one boy told WCVB-TV last month. "And then a shark," added his friend.

This summer, there have been several shark attacks in the Carolinas and most of the victims have been children. In July, Lucy Mangum, 6, was with her parents and sister at Ocrakoke Beach on the Outer Banks when a shark bit her leg.

"I heard her scream so I immediately turned toward her and at that point saw the shark right next to her," her mother, Jordan Mangum, told ABC News a few days after the attack.

Deaths Caused by Sharks Down

Statistics show that unprovoked shark attacks have risen sharply in the last 110 years but fatalities are down.

"In the Malibu waters, it's like a nursery for shark," said Carter Crary, the owner of Malibu Divers. He said that a type of fishing net had been banned in California in the 1990s, making it easier for sharks to reach the shores.

"Sharks aren't that dangerous," Crary said. "You're more likely to get killed by a toaster or vending machine."